Small packets, long journey

Computing · Computer Systems · ages 15-16

Name ______________________ Date ____________

What do packet numbers allow at arrival?
- Rebuilding the message in order
- Faster screen colours
- Free extra data
Why travel in packets rather than one stream?
- Packets look prettier
- Streams are banned
- Chunks can split routes, share links and dodge damage
Packets sometimes arrive out of order.
Circle one: True False
A receiver expects 37 but sees 73. What does it know?
- A packet between is missing or late
- Everything arrived perfectly
- The sender has finished
A sender gets no acknowledgement before its timer ends. What does TCP do?
- Deletes the whole message
- Sends the packet again
- Closes the internet
What is a protocol?
- A fast cable under the sea
- Agreed rules for addressing, sending and checking
- A brand of router
Mail needs completeness while a live game needs speed. Which pairing fits?
- Mail over UDP, game over TCP
- Mail over TCP, game over UDP
- Both over bare IP
A video call breaks into squares yet keeps going. What does that show?
- The screen is broken
- Packets travel in streams
- Most packets arrive while a few go astray

Answer key

For grown-ups. Fold this page away before handing over the rest.

Rebuilding the message in order · Numbers tame the chaos when chunks land jumbled.
Chunks can split routes, share links and dodge damage · Splitting trades tidiness for a tougher trip.
True · Separate routes mean separate timings, so jumbling is routine.
A packet between is missing or late · A jump past the expected number flags a gap in between.
Sends the packet again · An unanswered timer means resend. Better twice than never.
Agreed rules for addressing, sending and checking · Protocols let machines from different makers grasp each other.
Mail over TCP, game over UDP · Mail wants completeness, while live play wants raw speed.
Most packets arrive while a few go astray · Lost chunks show as squares while the surviving stream plays on.